Still No Spark

[RazeOrion]

Primary and secondary ignition coils testing well within their parameters. Battery charged amd putting out at least 11.7 volts. Got my new spark plug cables and new air filters delivered and installed. Checked with a multimeter to ensure cables from ignition coils all the way to the plugs are providing a solid connection.

Attempt to kickstart it because my electric start isn't working, which is another issue.

So far, still no spark. Any other guesses as to what it may be hindering my spark?

 

[tstidham]

Have you checked the kill switch is working properly? Maybe from the drop, something happened and it's stuck on kill? I had an issue with my signal switch and it turned out one of the solder connections inside the switch had basically cracked off inside. I was able carefully resolder it back on. Use a multimeter to check it has and loses continuity when switching it (i forget if it completes the power or grounds the circuit).

 

[gpounce32768]

Measure the resistance of both pickup coils- both should be between 100 and 600 ohms or so, measured to ground. If either is open or shorted there will be no spark. You can do it at the end of the harness that plugs into the TCI.

 

[RazeOrion]

Have you checked the kill switch is working properly? Maybe from the drop, something happened and it's stuck on kill? I had an issue with my signal switch and it turned out one of the solder connections inside the switch had basically cracked off inside. I was able carefully resolder it back on. Use a multimeter to check it has and loses continuity when switching it (i forget if it completes the power or grounds the circuit).

I'll give that a shot next weekend

 

[RazeOrion]

Measure the resistance of both pickup coils- both should be between 100 and 600 ohms or so, measured to ground. If either is open or shorted there will be no spark. You can do it at the end of the harness that plugs into the

Have you checked the kill switch is working properly? Maybe from the drop, something happened and it's stuck on kill? I had an issue with my signal switch and it turned out one of the solder connections inside the switch had basically cracked off inside. I was able carefully resolder it back on. Use a multimeter to check it has and loses continuity when switching it (i forget if it completes the power or grounds the circuit).

Well that would explain my potential electric start issue. But the main issue I have is no spark on kickstart either.

I pulled my TCI and it looks like there might have been a component that burnt out? Plastic protector sheet has a dark spot pretty close to a capacitor, but it could be something else.

 

[gpounce32768]

Nothing looks blown up from this perspective- that goop all over is conformal coating. If something did burn out I'd be expecting burns/melting on the inside- more than a spot. The move would be to remove the screws and lift the board to check the back side.

 

[RazeOrion]

Nothing looks blown up from this perspective- that goop all over is conformal coating. If something did burn out I'd be expecting burns/melting on the inside- more than a spot. The move would be to remove the screws and lift the board to check the back side.

Yeah, most likely. I pulled it roughly 20m before I left for work, so I didn't have time to really break into it. I'll check it out tomorrow afternoon

 

[avemachina]

It might be the lighting, but I found a few spots that might be worth a once-over--a few of the resistors look a little oxidized (or it might be goo), and a pin on the IC looks a little corroded. Also, not sure what's happening on the board at C[apacitor]20, but if there is white junk, that's a potential sign that the electrolyte from that capacitor has made an ungraceful exit. If you have something like an awl, or a tiny electronics screwdriver, or needle-end tweezers, you can try gently scraping the corroded bits away.

 

[RazeOrion]

Thanks for the scan. I'll definitely give them a better look after some sleep

 

[avemachina]

One more thing, just a quick primer on electronic components in case you aren't familiar with them.

 

[gpounce32768]

C20 doesn't look like its swollen OTOH electrolytic caps can fail in a variety of ways- a closeup definitely necessary to tell more. Same with pin 2 of the IC- that does look weird. The oxidized resistor leads don't bother me, assuming the solder joints are good.

 

[RazeOrion]

I removed the board and took some new photos of the aforementioned potential problem areas. There don't seem to be any burn marks on the back.

The 4 resistors avemachina pointed out seem to have a coating on them, but don't feel oxidized. I'm noticing the capacitors near the IC-transistors seem like they could be burnt out, but I'm a layman so I'm not 100% sure.

Uploading new photos for better views.

Worst case scenario, I drop money on a "new" one.

 

[gpounce32768]

No sign of heat damage on the bottom of the board.

Those caps don't look failed- that goop on them is the conformal coating which helps prevent vibrations from fatiguing the solder and when properly applied, helps prevent moisture intrusion.

If the caps leaked electrolyte, it would be big goopy mess surrounding the base of the caps, sometimes associated with the tops bulging, or even rupturing. That said, they can also fail without drama. I repaired a '70's amplifier which had about a half dozen capacitors which failed by leads rotting out of the case. Others can fail just by becoming leaky and/or losing capacitance. I've only seen one fail from leaking electrolyte.

There are a variety of capacitor checkers that can test them but if you go to the trouble of removing some you might as well remove and replace them all with new ones. If you're inclined to do that, experiment with cutting through that coating on an empty part of the board so you can be sure to free the capacitors without damaging adjacent parts.

 

[RazeOrion]

No sign of heat damage on the bottom of the board.

Those caps don't look failed- that goop on them is the conformal coating which helps prevent vibrations from fatiguing the solder and when properly applied, helps prevent moisture intrusion.

If the caps leaked electrolyte, it would be big goopy mess surrounding the base of the caps, sometimes associated with the tops bulging, or even rupturing. That said, they can also fail without drama. I repaired a '70's amplifier which had about a half dozen capacitors which failed by leads rotting out of the case. Others can fail just by becoming leaky and/or losing capacitance. I've only seen one fail from leaking electrolyte.

There are a variety of capacitor checkers that can test them but if you go to the trouble of removing some you might as well remove and replace them all with new ones. If you're inclined to do that, experiment with cutting through that coating on an empty part of the board so you can be sure to free the capacitors without damaging adjacent parts.

Thanks for the tips! My younger brother has electrical engineering experence and hes wants some more soldering practice.
Time to pass this to someone with a little more electrical engineering knowledge than me, haha.

Thankfully, we have all the equipment/knowledge required to actually desolder and resolder everything from scratch. Could even replace every single component, if need be, but I'd like to avoid that if possible, haha.

 

[RazeOrion]

Have you checked the kill switch is working properly? Maybe from the drop, something happened and it's stuck on kill? I had an issue with my signal switch and it turned out one of the solder connections inside the switch had basically cracked off inside. I was able carefully resolder it back on. Use a multimeter to check it has and loses continuity when switching it (i forget if it completes the power or grounds the circuit).

I will definitely give this a look over my weekend. I'm definitely buying a new one anyway, just due to how worn/old the assembly looks. Text worn off, loose fitting, crack here and there, etc.

 

[gpounce32768]

Thanks for the tips! My younger brother has electrical engineering experence and hes wants some more soldering practice.
Time to pass this to someone with a little more electrical engineering knowledge than me, haha.

Thankfully, we have all the equipment/knowledge required to actually desolder and resolder everything from scratch. Could even replace every single component, if need be, but I'd like to avoid that if possible, haha.

Every part you remove adds risk of damage (eg breaking a trace or an adjacent part), so its helpful to focus on likely sources of failure. 30+ yr old electrolytic caps are somewhat prone to failure, but its interesting how many don't. I have seen a just a few cases of failed resistors, but very few compared to electrolytics.

Its also easier to replace the caps because the ratings are printed on the cans. The 2 big driver transistors should also be at least tested for the proper diode drop to have confidence they are OK. Those can easily be replaced if you want to- not critical. The resistors have their color codes of course, but there are quite a few so it'd be better to measure each and see if they're at least close though sometimes the circuit composition doesn't permit.

 

[avemachina]

You mentioned your electric start doesn't work, which might be the culprit. There's a connection from the TCI to the killswitch/start button that restricts if the bike will send charge to the coils. Here are a handful of suggestions to check:

- Silly but important: is your IGNITION fuse good?

- Try switching your plug wires around. Sometimes folks accidentally use the wrong-side connectors for the coil, so it fires the wrong cylinder.

- When you press your clutch lever in, do you hear a click from under the battery? There's a switch connected to the clutch lever that doesn't let you start the bike if it's in gear, UNLESS that switch is open (clutch lever pulled in). The click is a relay. You won't get any start if it thinks it's in gear with the clutch lever released.

- Take the killswitch off the bar and look inside. Do the wires and connections look OK? When you put it back on the bar, is there a metal-to-metal connection between some part of the switch body and the handlebars? This switch needs to be grounded, so it won't work if there's corrosion or a coating/paint in the way.

- Check your pick-up coil position. Make sure when your engine is at the LF mark, the rotor is aligned with the top bar on the coil.

 

[RazeOrion]

*UPDATE**

I got her running! You'll never believe the problem...a bad 10A fuse for my ignition system

In any case, my next course of action is a carburetor cleaning

 

[CaptChrome]

Silly but important: is your IGNITION fuse good?

You'll never believe the problem...a bad 10A fuse for my ignition system

@avemachina believed it, and suggested it - good job!

 

[RazeOrion]

@avemachina believed it, and suggested it - good job!

Main reason I checked it.

We tested from battery to ignition switch, coils to the battery, etc, etc.

Finally narrowed down the fuses. All tue fuses had a generous amount of scale, but the ignition fuse was practically all scale. Quick trip to Autozone, and a replacement of all my fuses, she fired right up.

Quick list of needed fixes:
- Carb Rebuild
- Blinkers
- Rear Brake Light
- Electric Start
- New Mirrors
- New Handlebars
- Gas Tank Repair
- Much, Much More